In the scene where James Bond escapes from Largo's pool, by swimming through an underwater tunnel past several sharks, James Bond (Sean Connery) puts his hands flat against a protective glass inbetween him him and the sharks making it obvious he is in no real danger.
I read in a book that the production team ran out of protective glass and Sean Connery was, unknown to him, exposed to real danger from the shark, hence his expression of concern.